The coil in Fig. $28-50$ carries current $i=2.00 \mathrm{~A}$ in the direction indicated, is parallel to an $x z$ plane, has $3.00$ turns and an area of $4.00 \times 10^{-3} \mathrm{~m}^{2}$, and lies in a uniform magnetic field $\vec{B}=(2.00 \hat{\mathrm{i}}-3.00 \hat{\mathrm{j}}-4.00 \hat{\mathrm{k}}) \mathrm{mT} .$ What
are (a) the orientation energy of the coil in the magnetic field and
(b) the torque (in unit-vector notation) on the coil due to the magnetic field?